Railway-traffic-controlling apparatus



R. M. GILSON RAILWAY TRAFFIC CONTROLLING APPARATUS March 6, 1928. 1,661,175

Filed Sept. 22, 1929 INVENTOR 1 Q Z'W Patented Mar. 6, 1928.

UNITED STATES PATENTOFFICE.

ROBERT M. GILSON, or PITTSBURGH, PENNSYLVANIA, issxoNon. TO THE NNION SWITCH & SIGNAL COMPANY, or SWISSVALE, PENNSYLVANIA, A CORPORATION 01? PENNSYLVANIA.

RAILWAY-TRAFFIC-CONTROLLING APPARATUS.

Application filed September 22, 1926. Serial No. 186,931.-

My invention relates to railwa traflic controlling apparatus, and particu arly to ap-.

paratusof the typecomprising train carried governing means controlled by energy received from the trackway. More particularly my present invention relates to the trackway portion of such apparatus.

I will describe one form of trackway apparatus embodying my invention, and will then point out the novel features thereof in claims. The accompanying drawing is a diagrammatic view illustrating one form of trackway apparatus embodying my invention.

Referring to the drawing, the reference characters 1 and l" designate the track rails 'of a stretch ofrailway track over which trafiic normally moves in the direction indicated by them-row. These trzwk'railsarc divided into a plurality of successive track sections AB, BC, etc. by pairs of insulated joints 2. For convenience of installation it is often desirable to locate the insulated joints 2 between the endsof existing rail sections. Under these conditions it usually happens'that the joints of each pair are staggered and the joints are so illustrated in the drawing.

Each track section is provided with a 3|) track relay designated by the reference character R with an exponentcorresponding to the location andco'mprising two windings 7 and 8. -Winding 8 of each track relay is constantly supplied with alternating current from a suitable source such as an alternator M, over line wires 3 and 3. Finding 7 of each track relay is constantly connected across the rails adjacent the entrance end of the corresponding section. Track circuit current is suppliedto each section from a track transformer designatedby the reference character T with a suitable exponent and having its secondary 4 constantly connected through the usualimpedance 5 across the rails adjacent the eixit end ofthe section. It'follows that when primary 6 of a track transformer T is supplied with alternating current as will be described herein-. after, the track relay for the corresponding section is energized. i

Means are also provided for supplying each track section with alternating loop ourrentwhich flows through the rails of the 'when the track rela section is provided'with two impedances 12 and 13 connected across the rails adjacent the entrance end andthe exit end, respec tively, of the section. Each section is also provided wit-ha loop transformer designated y the reference character L with an exponent corresponding to the location and havmg the terminals of its secondary 9 connected with the mid-points ofthe impeda nces 12 and 13 for the corresponding sect on. The primary 10 of each loop transformer is suppliedwith alternating current from line wires 3 and 3 over frontcontact all of the track relay for the section next in advance. It follows that each section is supplied with loop current when and only j for the section next in advance is energizer. Before explaining the operation of the apparatus it should be stated that the track- 'way apparatus herein shown and described is suitable for, thoughin no way governing means arranged to give aproceedindication on board the train when the rails occupied by the train are supplied with track circuit current and also with loop current. Should the supply of either track circuit current or loop current for any reason he interrupted, a stop indication is received on board the train.

As shown in the drawing, the section to the right of point C is unoccupied and track relay 'l'l tis energized. Current is therefore supplied to primary 10 of transformer L i and track circuit current and loop current areboth supplied to the rails of section bridging the rails between the staggered in sulated joints 2 adjacent point B. This train of course (la-energizes relay R opening front contact 11 thereon and de-energizing transformer" L. A second train V 00- copying section AB is therefore deprived of loopcurrentfrom transformer L and a stop indication is received on board this train. i b

With only the apparatus thus far described, however, and with the train V in theposition illustrated in the drawing, ourrent from transformer T might flow from the left-hand terminal of secondary i of transformer T through rail 1 of section to the rear truck 20 of the train V thence through rail 1 of section 6 and through the ground to the rails l and 1*" of section A-B in rear of train V lhis current might then flow through the rails of section rrl5 in parallel to the forward axles of the train and return to the secondary at of transformer T through rail 1 of section frl5 and impedance Under these conditions, that is, when current is flowing from transformer '1 over the circuit just traced, alternating current lion's through the rails in parallel beneath the train V and this current might serve as loop current to actuate the train carried apparatusvto give a false proceed indication on board the train,

although the section next in advance is cocupied so that train V should receive a stop indication. Obviously, this is a dangerous condition and in order to prevent its occurrence, I connect a source of direct current, such as a battery designated by the reference character K with an exponent corresponding to the location, across the rails between the insulated joints 2 which separate each two adjacent sections. 1 also connect a direct current checking relay, designated by the reference character 1) with an exponent corresponding to the location, across the rails between each pair of staggered insulated joints in parallel withthe associated battery K. The primary 6 of each transformer T is then supplied with alternating current from line wires 3 and 3% over a front cont t of the adjacent checking relay D. [h this arrangement each checking relay energized by current from the adjacent battery K, except when the wheels and axles of a train occupy that portion of the-track hetween the associated pair of joints. For example, relay D is normally energized but is file-energized under the conditions shown in the drawing by the wheels and axles of truck of the train V With the train V in the position illustrated in the drawing, front contact 15 of relay D is open so that no track circuit current is being supplied to the rails ofsection AB. Train V is therefore deprived of track circuit current and a stop indication, is received on board the train even should the train receive false loop cur- "rent from an adjacentsection.

,A reactor is; is interposed between each battery K and one of the track rails in order to prevent theflow of alternating loop or track circuit current from one track section to the rails of an adjacent track section in suilicient magnitude to effect governing means in the latter section.

It should also be pointed out that the connections of the track transformers are such that the relative instantaneous polarities of the track circuit currents supplied to all track sections are the same, and the track relays R are arranged to be pickedup by current ofthis polarity. Should one of the reactors 14: or one of the checking relays become short circuited, track circuit current might flow from one section into an adjacent section. For example, I will assume that checkmg relay D or reactor 14; ad acent point 13 becomes short-circuited, thereby es- But it should be pointed out that current thus supplied to relay R would be of a relative polarity opposite to that which can pick up the relay and the result of the stray current thus supplied to the relay would be to hold the front contact of the relay open.

It follows that short circuiting of the check 7 mg relay D or a reactor 14; can not cause nn-- proper operation of an adjacent track relay.

Although I have herein shown and described only one form of railway traflic controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is: i

1. Railway trafiic cont-rolling apparatus comprising a stretch of railway track divided into a plurality of successive track sections by pairs of staggered insulated joints, a track relay for each section, means controlled by each track relay for supplying loop cur rent to the rails of the sectionnext in rear, a source of energy connected across the rails between the joints of each pair, a checking relay also connected across the rails between the joints of each pair, and means controlled by each checking relay for supplying track circuit current to the rails ofthe sectionnext in rear. 7 j i 2. In combination, a stretch of railway track divided into a plurality of successive track sections by pairs of staggered insulated joints, a checking relay and a source of energy connected in parallel across the rails between the joints of each pair, and means controlled-by each checking relay for sup lying track circuit currentto the mile 0 an adjacent section.

3. Railway trailic controlling apparatus comprising a stretch of railway track div ded into a plurality ,ofsuccessive "track each section, means controlledby each track relay for supplying alternating loop' current to the rails of the section next in rear, a

source of direct current and a direct current checking relay connected in parallel across the rails between the joints of each pair, and

means controlled by each checking relay for sup lying alternating track circuit current to t e rails of the section nextin rear.

4. Railway traific controlling apparatus comprising a stretch of railway" track divided into a plurality of successive track sections by pairs of staggered insulated joints, an alternating current track relay for each section, means controlled by each track relay for supplying alternating loop current to the a rails of the section next in rear, a source of direct current and a reactor connected in series across the rails between the joints of each pair, a'checking relay also connected across the rails between the joints of each pair, and means controlled by each checking relay for supplying alternating track circuit currentto the rails of the section next in rear.

sections by pairs of staggered insulated oints, an alternating current track relay fortrack sections b pairs of staggered insulated joints, 9, two-e ement track relay for each section, each track relay having one winding connected across the rails of the associate section and having the other winding constantly su plied with alternatin current, a source of irect current and a re ay connected in parallel across the rails between the joints of each pair, areactor interposed between each such source of direct current and one rail, and means controlled by each checking relay for supplying alternating current-to the rails of the section next in rear in such manner that the instantaneous relative polarit of the alternating currents supplied to al sections are the same whereby each track relay may be picked up by current from the rails of the associated section but can not be picked up by stray current from an adjacent section should a checking relay or its associated reactor becomeshort circuited.

In testimony whereof I afiix my signature.

ROBERT M. GILSON.

5. In combination, a stretch of railway 7 track divided into a plurality of successive 

